The Château de Beaucaire is a ruined castle in the commune of Beaucaire. Existing structures date from the 12th and 16th centuries, with other elements from various times in the Middle Ages.
First built in the 11th century, the castle was torn down on Richelieu's orders. It used to be protected by a wall, the trace of which can still be followed. It includes a strange polygonal tower perched on a rocky spur, the façades dominating the sheer drop, and a fine round corner tower. Once inside the walls, a staircase leads to a small Romanesque chapel with a charming, sculpted tympanum, and then to the musée Auguste Jacquet. The museum has exhibits on the region's archaeology (dating back more than 40,000 years) and popular arts and traditions.
References:Ehrenbreitstein Fortress was built as the backbone of the regional fortification system, Festung Koblenz, by Prussia between 1817 and 1832 and guarded the middle Rhine region, an area that had been invaded by French troops repeatedly before. The fortress was never attacked.
Early fortifications at the site can be dated back to about 1000 BC. At about AD 1000 Ehrenbert erected a castle. The Archbishops of Trier expanded it with a supporting castle Burg Helferstein and guarded the Holy Tunic in it from 1657 to 1794. Successive Archbishops used the castle's strategic importance to barter between contending powers; thus in 1672 at the outset of war between France and Germany the Archbishop refused requests both from the envoys of Louis XIV and from Brandenburg's Ambassador, Christoph Caspar von Blumenthal, to permit the passage of troops across the Rhine.